There were also political expediencies which prevented full prosecution of those responsible in Japan. If there had been any justice, Hirohito should have come to his finish at the end of a rope in 1946, but politics prevented this.
I agree with you, Hirohito should have been executed. In spite of revisionist history that claims he was a puppet, he started the war and he ended it. The latter is why MacArthur allowed him to live, it was incredible how almost all the people immediately transitioned to peace, after being such bitter enemy's! It would not have happened with out the Emperor. One strange cultural difference happened when the American delegation went to meet with Hirohito. As they were being driven to the Palace, they noticed all the Japanese solder's lining the roads had their backs turned. The Americans were deeply offended at what they perceived as an insult. They had to be told that surrender was the greatest shame for all the Japanese forces, and they felt they were no longer worthy to look into the eyes of the victors! Still, I did not cry when the little man died!